Residents from Newtown, Connecticut, where 20 children and six teachers were killed in an elementary school shooting, are joining a march on Washington for gun control on Saturday with parents, pastors, and survivors of gun violence.

Organizers said they are expecting thousands of participants for the rally on the National Mall, including about 100 from Newtown, and buses from New Jersey, New York and Philadelphia. Others are flying in from Seattle, San Francisco and Alaska.

They will gather Saturday at the Capitol Reflecting Pool and will begin marching down Constitution Avenue toward the Washington monument shortly before midday. A rally is planned on the monument grounds at noon.

Molly Smith, the artistic director of Washington's arena stage, and her partner organized the march, inspired by the December massacre that killed 20 first graders and six teachers at Sandy Hook elementary school in Newtown, she said. The gunman also fatally shot his mother and killed himself.

"With the drum roll, the consistency of the mass murders and the shock of it, it is always something that is moving and devastating to me. And then, it's as if I move on," Smith said. "And In this moment, I can't move on. I can't move on.

"I think it's because it was children, babies," she said. "I was horrified by it."

While she's never organized a political march before, Smith said she was compelled to press for a change in the law. The march organizers support President Barack Obama's call for a ban on military-style assault weapons and high-capacity ammunition magazines as well as for universal background checks for gun sales. They also want lawmakers to require gun safety training for all buyers of firearms.

After the Connecticut shootings, Smith posted something on Facebook and drew more support to do something. The group One Million Moms for Gun Control, the Washington National Cathedral and two other churches eventually signed on to co-sponsor the march. Organizers have raised more than $46,000 online to pay for equipment and fees to stage the rally.

Lawmakers from the District of Columbia and Maryland are scheduled to speak. Actress Kathleen Turner is expected to appear, along with Marian Wright Edelman of the Children's Defense Fund and Colin Goddard, a survivor from the Virginia Tech massacre.

Smith said she supports a comprehensive look at mental health and violence in video games and films. But she said the mass killings at Virginia Tech and Aurora, Colorado, and Newtown all start with guns.

"The issue is guns. The second amendment gives us the right to own guns, but it's not the right to own any gun," she said. "These are assault weapons, made for killing people."